Thumbnail of Turkish History
They turned the great Byzantine cathedral into a mosque and settled down to enjoy city life before starting on a second wave of conquest, this time as the Ottoman Empire. This Turkish wave hit its peak in the 16th century, when the Turks smashed the Hungarians at Mohacs (1526), grabbed most of the Balkans, and pushed south and east into Persia and Arabia.
The Europeans got scared enough to unite for once against the Muslim threat. That's how you know the Europeans are really, really scared: when those quarrelsome bastards actually stop bitching and work together. A combined European fleet crushed the Ottoman galleys at Lepanto (1571) in the Mediterranean. But the Turks hadn't run out of steam. They said to the Europeans, "You have only shaven our beard, and the shaven beard grows faster."